Understanding Kawasaki Disease

SINGAPORE — Just seven months old, Ihsan takes aspirin, crushed and mixed with water, every day.

The blood-thinning medication was given after he developed heart complications from Kawasaki Disease (KD) last month, said Ihsan’s mother Mdm Nadirah Pasuni.

The 37-year-old teacher has withheld her baby’s surname because of privacy issues.

KD is a childhood illness whereby blood vessels throughout the body become inflamed.

Although Ihsan’s condition was eventually diagnosed and treated, he developed a coronary aneurysm — an abnormal enlargement of the artery that can cause heart problems in the future. Only about 5 per cent of children with KD develop this.

A coronary aneurysm is dangerous because it can lead to blocked blood flow to the heart, decrease heart function, or cause abnormal heart rhythms or sudden death, said Associate Professor Tan Teng Hong, head and senior consultant at Cardiology Service, Department of Paediatric Subspecialties at KK Women’s and Children’s Hospital (KKH).

Aspirin lowers the risk of blood clotting in the dilated coronary arteries, which can lead to a heart attack.

LACK OF AWARENESS

Every year, KKH sees approximately 120 to 150 new cases of KD. Nine in 10 patients seen at the hospital are under the age of five, of whom 40 per cent are babies under one year old, such as Ihsan. Adults can get KD too, but this is extremely rare.

According to Assoc Prof Tan, KD is currently the most common acquired heart disease in children in developed countries. Yet, most parents are not aware of the disease and its potential long-term health complications.

Before her baby was diagnosed, Mdm Nadirah had never heard of the disease. A third-time mum with two older daughters aged nine and six, Mdm Nadirah initially thought that Ihsan’s fever was “one of those normal illnesses kids get”.

However, Ihsan’s high fever did not let up despite repeated visits to the doctor. He also developed red eyes, rashes on his body and cracked, bleeding lips. By the sixth day, he was so lethargic that his worried parents took him to the children’s emergency department.

“When the doctor said my baby could have KD, I was shocked. What is this disease? I had never heard of it, much less know what to expect from it,” said Mdm Nadirah.

What exactly causes the inflammatory disease, which appears to be more common in Asians than in Caucasians, is still a mystery to doctors. One theory is that the inflammation is likely to be “an overly intense immune reaction, triggered by some common childhood infection”, said Assoc Prof Tan.

NO STANDARD DIAGNOSTIC TEST

Even in experienced hands, diagnosing KD can be challenging. There is also currently no standard method to diagnose the disease.

Doctors typically diagnose the disease by checking for various clinical symptoms, including high fever for at least five days, red eyes, cracked lips and swollen tongue, skin rash and swollen lymph nodes in the neck. The child may also experience swelling, and peeling of the skin on their hands and feet.

However, not all symptoms appear in each patient, and they may not all come at the same time, said Assoc Prof Tan. He said: “Diagnosing KD can sometimes be very difficult and the chances of missing the diagnosis are high, especially in the early part of the illness.”

During Ihsan’s three-day hospital stay, doctors ran a barrage of tests to exclude other childhood conditions. This is an essential step as KD symptoms are also similar to those of other childhood conditions such as measles, drug allergy, sepsis, scarlet fever and autoimmune disease, said Assoc Prof Tan.

“I call those three days of hospitalisation my dark days,” said Mdm Nadirah.

“While waiting for the test results, we were frightened and worried. The lack of sleep and my baby’s extreme crankiness from being ill further worsened our anxiety.”

Once the diagnosis was confirmed, Ihsan was treated using intravenous immunoglobulin (IVIG), which is derived from donated plasma. Administered in the hospital through the veins, IVIG can help to reduce the risk of heart problems, said Assoc Prof Tan.

With the right intervention, most children make a full recovery. Without treatment, a quarter of children with KD develop coronary aneurysms, said Assoc Prof Tan.

SUDDEN HEART ATTACK

Ihsan will go for a follow-up heart scan in three months’ time, before his doctor decides on the next course of action.

Mdm Nadirah worries about Ihsan’s heart complications but said there is not much she can do, except to “offer lots of prayers” and ensure that he takes his aspirin regularly.

“How will this (coronary aneurysm) affect my son in the future? As a parent, I worry that he might one day have a sudden heart attack,” said Mdm Nadirah.

To learn to cope with her son’s condition, Mdm Nadirah has also joined a newly formed local support group for parents and caregivers of children with KD. Formed by six local mums, the group offers support by phone or email to affected families.

“I was initially hesitant to give Ihsan aspirin regularly as I was worried about over-medicating him. However, when I learnt that the other parents in the support group are doing the same for their children, who are doing well with medication, that eased my worries.”